Electric lock



1944- K. J. J. MOGOWAN ELECTRIC LOCK Filed Dec. 10, 1943 5 Sheets-Sheet 1 H111 ATTORNEY Oct. 24,1944. K. J. .1. MQGOWAN ELECTRIC LOCK Filed Dec. 10, 1943 3 Sheets-Sheet 2 Patented Oct. 24, 1944- ELECTRIC LOCK Kenneth J. J. McGowan, Pittsburgh, Pa., assignor to The Union Switch and Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application December 10, 1943, Serial No. 513,661

6 Claims.

My invention relates to electric locks, and particularly to looks for preventing the unauthorized operation of railway trafiic controlling devices such as switches, derails, or the like.

One object of my invention is to provide a simplified form of electric lock which is particularly suitable for use in connection with a manually operated switch operating mechanism of the type shown and described in Letters Patent of the United States No. 2,184,870, granted to Herbert L. Bone and myself on December 26, 1939.

Another object of my invention is to provide a lock which can be bolted directly to switch operating mechanism of the type above referred to, and which thereby eliminates the necessity for separate tie mounting for the lock and the possibility of any shifting in position between the lock and the switch operating mechanism.

A further object of my invention is to provide an electric lock which does not require a lever lock rod.

A still further object of my invention is to provide an electric lock in which the contacts are more accessible than in previous forms of locks.

According to my invention, the lock is disposed in a casing which is constructed to bolt onto the end of the switch operating mecha nism in place of the guide plate which guides the one end of the lock bar of the mechanism, and includes an auxiliar lock rod which is movable between two extreme positions. This lock rod cooperates with the lock bar of the switch operating mechanism insuch manner that the auxiliary lock rod can only be moved between its two extreme positions when said lock bar occupies its locking extreme position, and that when the auxiliary lock rod is moved to said one extreme position and said lock bar is moved away from its locking position, said auxiliary lock rod will be retained in its one extreme position until said lock bar is returned to its locking position. Said auxiliary lock rod is biased to an intermediate position by spring means, and is operatively connected with a foot pedal by virtue of which it may be moved from its intermediate to its one extreme position. The casing of the lock is provided with a jaw which receives the hand throw lever of the switch operating mechanism when and only when the switch operating mechanism occupies its normal extreme position, and the foot pedal is operatively connected with a lever latch which projects into the path of movement of the hand throw lever into or out of said jaw when said auxiliary lock rod occupies its intermediate or its other extreme position but not when it is moved to its one extreme position. The lever latch is provided with an eye through which a padlock may be inserted when and only when the lever latch occupies its other extreme position, and which when the padlock is inserted cooperates with the padlock to prevent movement of the lever latch and connected parts away from the corresponding extreme positions. The auxiliary lock rod is formed with a notch which cooperates with a dog operated by the armature of an electromagnet. The cooperation between the notch and the dog is such that the dog will enter the notch when the magnet is deenergized and the auxiliary lock rod occupies its intermediate or its one extreme position, but will be withdrawn from the notch when the magnet is energized, and that, when the dog is within the notch movement of the auxiliary lock rod from its other extreme position to its intermediate position is permitted, but movement beyond its intermediate position toward its one extreme position is prevented. The auxiliary lock rod further carries a, cam dog H2 which cooperates with a pivoted arm to operate contacts whenever the auxiliary'lock rod is moved away from its other extreme position. The arm carries adjustable screws which cooperate with a bracket attached to the armature, and is biased by springs to a position determined by the released position of the armature so that the springs assist in biasing'the armature to its released position. The armature bracket also operates other contacts when the armature" is moved to its attracted position.

Other objects and characteristic features of my present invention will become apparent as the description proceeds:

Electric locks embodying my invention are an improvement upon those shown in Letters Patent of the United States No, 1,126,834, grantedto W. P. Neubert etal., on February 2, 1915, and also upon those shown and described in a c'opending application for Letters" Patent of the 7 United States Serial No. 513,707, filed by H. L. Bone on December 10, 1943.

I shall describe one form of electric lock embodying my invention; and shall then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a top plan view showing a railway switch operated by a switch operating mechanism provided with a switch lock embodying my invention. Fig. 2 is an enlarged top plan view of the switch operating mechanism shown in Fig. 1, the cover and some of the parts of the mechanism being removed and others of the parts being shown in section to better illustrate the construction of the remaining parts. Fig. 3 is a vertical longitudinal sectional view of the mechanism shown in Fig. 2 taken substantially on the line IlIIlI of Fig. 2. Fig. 4 is a detail view of the motion plate of the mechanism shown in Figs. 2 and 3. Fig. 5 is an enlarged transverse sectional view of the electric lock embodying my invention. Fig. 6 is a detail sectional view taken on the line VIVI of Fig. 2.

Similar reference characters refer to similar parts in each of theseveral views.

Referring first to Fig. 1, the reference character A designates a railway switch comprising, as usual, two fixed rails I and la and two movable rails or switch points 2 and 2a. The fixed rails l and la are laid on tie plates 3, and are secured to crossties 4 in the customary manner. The movable rails 2 and 2a are fastened together by a front rod 5 and a head rod 6, and may be moved into a normal or'a reverse position by means of a throw rod 1 which is connected with the head rod 6 through the medium of a switch basket 8. When the switch occupies its normal position, in which position it is shown in the drawings, the movable rail 2 engages the fixed rail l, and the movable rail 2a is spaced from the fixed rail la. When the; switch is reversed,

however, the movable rail 241 then engages the fixed rail la, and the movable rail 2 is spaced from the fixed rail i.

Secured to an elongated pair of the ties 4 adjacent the outer side of the rail l is a switch operating mechanism B for operating the switch A. This mechanism in the form here shown is identical in all essential respects to that described and claimed in Letters Patent of the United States No. 2,184,870, granted to Herbert L. Bone and myself on December 26, 1939, and it is believed, therefore, that for the purpose of my present invention the following brief description of this mechanism will suffice.

As best seen in Figs. 2, 3 and 4, the mechanism B in the form illustrated comprises a suitable housing In which encloses the operating parts of the mechanism, and which is closed at its upper end by a removable cover H. Located within the housing In is a motion plate (see Fig. 4) which is guided to slide longitudinally in a direction parallel to the track by means of guide rollers 26 and 21, secured to the underside of the motion plate adjacent its opposite ends, and cooperating with guideways 28 provided on the bottom wall of the casing. The motion plate 25 has rack teeth 29 formed in its upper surface, which teeth mesh with a segment gear 30 mounted on a square shaft 3|. The shaft 3| is mounted at its ends in bearing sleeves 32 and 33 journaled in bosses 34and 35 formed in the sidewalls of the casing, and has secured. thereto at its outer end adjacent to the sleeve 32 a hand throw lever;

38 which serves as a means for reciprocating the motion plate between its two extreme positions. A roller 40 is secured to th underside of the .motion plate 25 adjacent one side thereof at a point equally spaced from the rollers 26 and 21, and this latter roller cooperates with cam faces 4| and 42 formed on an escapement crank 43 (see Fig. 2). The escapementcrank 43 is formed integrally with the upper end of a switch actuating shaft 44, the shank of which is provided with two bearing surfaces 45 and 45 separated by .a

squared portion 41. The bearing surfaces 45 and 4B are journaled in vertically aligned bearings 48 and 49 formed respectively in the bottom of the housing l0, and in a depending stirrup 50 which is provided on the underside of the casing, and secured to the square portion 4'] of the shaft is a removable switch operating arm 50a which is pivotally attached to the free end of the throw rod I.

A lock bar 5| extends longitudinally of the housing l0 directly above the motion plate 25, and is slidably mounted adjacent one end in a guideway formed in the casing 50 of an electric lock which is bolted to the end of the housing 10, and which embodies my present invention. The other end of the lock bar is slidably mounted in a guideway 54 (see Figs. 3 and 4) formed in a frame 55 which is bolted to the casing adjacent its left-hand end, and which serves as a support for a circuit controller. The lock bar is operatively connected with the motion plate by means of a stud 51 secured to the lock bar and extending into a transversely extending slot 58 formed in the upper side of the motion plate. The parts are so proportioned that when the casing is secured to the housing In, the stud 51 will be held in operative engagement with the motion plate.

The left-hand end of the lock bar 51 cooperates with a notch 59 provided in a lock rod L which is secured to the front rod 5. The parts are so proportioned that the notch 59 will align with the lock bar when and only when the switch occupies its full normal Position, and that, when the notch 59 is in alignment with the lock bar, and the motion plate is in its left-hand extreme position, the lock bar will have entered the notch 59, as shown in Fig. 3, and will thus have locked the switch in its normal position.

The operation, as a whole, of the portion of the apparatus thus far described is as follows: When the hand throw lever 38 is rotated to its normal extreme position in which it is shown in the drawings, the motion plate 25 is moved to its extreme left-hand or normal position in which it is shown in Figs. 2 and 3, and under these conditions, the switch points are held in their normal positions by engagement of the roller 48 with the cam surface 41 of the escapement crank 43. Furthermore, under these conditions, the lock bar 5! enters the notch 59 in the lock rod L, thus locking the switch points in their normal positions.

When it is desired to reverse the switch, the hand throw lever 38 is rotated in a counterclockwise direction through an angle of substantially from the extreme position shown to its opposite or reverse extreme position. This rotation of the hand throw lever acts through the segment gear 38 and rack teeth 29 to move the motion plate to its right-hand extreme position, and as the motion plate moves to this latter position, the first part of the movement withdraws the lock bar 5| from the notch 59 in the 1001; rod L to unlock the switch, the intermediate part of the movement causes the roller 40 to engage the cam surface 42 of the escapement crank 43 and rotate the escapement crank to the position in whichthe straight portion of the cam surface 42 extends parallel to the track, thereby rotating the switch actuating shaft to its reverse extreme position, and hence moving the switch points to their reverse extreme positions, while the final part of the movement of the motion plate causes the roller 40 to move along the straight portion of the cam surface 42 to such a position that any tendency of the switch actuating shaft to rotate in a direction to permit the switch points to move away from their reverse positions is eifectively blocked by the roller. It will be seen, therefore, that when the switch points occupy their reverse extreme positions, they are effectively held in these positions due to the coaction between the roller and the escapement crank, and it will also be seen that any force which may be exerted on the switch tending to restore it to its normal position will cause a transverse force to be exerted on the motion plate rather than a longitudinal force, thus vavoiding any tendency to reverse the hand throw lever due to any force which may be exerted on the switch.

When the switch has been moved to its reverse position, and it is desired to restore it to its normal position, the hand throw lever 38 is returned to the position shown. The operation of the parts under these conditions is exactly the reverse of that just described, and this operation will be apparent from the foregoing description and from an inspection of the drawings without further detailed description.

Referring now to the electric lock embodying my invention, the casing 66 of this look is closed at its upper end by a hinged cover 6| through which access to the interior of the casing may be had, and is provided at its forward side with an integral extension 62 formed with a jaw 63 which receives the hand throw lever 36 when the hand throw lever occupies its normal extreme position in which it is shown in the drawings. The extension 62 is also provided at one side with two spaced vertical standards 63 which support a pivot pin 65, and pivotally mounted on the pin 65 between the standards is a lever latch 66. This latch is movable between a latching position in which it is shown in Fig. 5, and an unlatching position, and is provided with a nose portion 66a which, when the latch occupies its latching position, projects into the upper end of the jaw in such manner that it prevents movement of the lever 38 into or out of the jaw, but which, when the latch is moved to its unlatching position, is withdrawn from the jaw. The latch is also provided with an eye 66b and with a treadle portion 660. The eye 66b is so disposed that the bow of a padlock 6'! can beinserted through the eye when and only when the latch occupies its latching position, and that, when the lock is in place in the eye, the bow of the lock will cooperate with the undersides of lips 64a formed on the standards 64 to lock the latch in its latching position. The treadle portion 660 of the latch provides a means for at times restoring the latch to its latching position following its movement to its unlatching position under certain conditions which will be made clear hereinafter.

Pivotally mounted between the standards 64 below the latch 66 on another pin 68 is a foot pedal 69 provided with a finger 69a which projects into and cooperates with a recess 6601 in the lower edge of the latch 66. The foot pedal 69 is also provided with depending slotted bifurcations 6% which straddle one end of a rod 70 slidably mounted in the extension 62 of the casing 60 below the jaw 63. The foot pedal is operatively connected with the rod 10 by a pin ll extending through the slots in the bifurcations and through a clearance hole in the rod 10.

The inner end of the rod 10 is adjustably 3 screwed into one end of an auxiliary lock rod 72 which is slidably supported in the bottom of the casing 66, and mounted on the rod 70 between the contiguous'end of the lock bar and a confronting shoulder 10a formed on the rod are two spring guides 92 and 93. The spring guides are disposed within a spring compartment 90 formed in the extension 62 of the casing 66, and support a coil spring 9! of such length that when both guides are engaging the associated end wall of the compartment 90, the spring will be partially compressed. The parts are so proportioned and the rod 10 is so adjusted that when both guides 92 and 93 are engaging their adjacent end walls of the compartment 90 and the rod 76 is midway between its two extreme positions, the shoulder 10 will just touch the spring guide 92 and the confronting end of the bar 12 will just touch the spring guide 93. It will be apparent, therefore, that the spring 9| acts through the spring guides to bias the lock bar to a position midwaybetween its two extreme positions. will also be apparent that when the lever latch is The lock bar 12 has a rectangular section to prevent it from turning, and is provided with two 5|. The notch 13 is of suificient length to permit the extreme posiverse portion 86 of a non-magnetic supporting bracket 84 secured to the bottom of the casing 66. The core is surrounded by an energizing winding 82, and is provided below the transverse portion 80 with an enlarged pole piece 83 which cooperates with a magnetizable armature 84. The armature is pivotally supported on trunnion supporting bracket 8|,

84a of reduced thickness which extends with clearance into a transverse slot 15a formed in the upper end of the dog 16. The magnetic circuit between the armature auxiliary lock rod 12 in such manner that the released position,

4- lock rod can only be moved between its two extreme positions when said lock bar occupies its locking position, and that when said lock rod is moved to its right-hand extreme position and said lock bar is subsequently moved away from its locking position said lock bar will enter the notch I4 in the lock rod and will thus retain the lock rod in its right-hand extreme position until the lock bar is returned to its locking position. As was pointed out hereinbefore, the auxiliary lock rod cannot be moved past its intermediate position unless the magnet 02 is energized, which energization will usually be controlled from a remote point, as will be explained more fully hereinafter.

The armature 84 of the magnet M in addition to controlling the movements of the dog I5, also controls the operation of a plurality of contacts each comprising a movable contact finger I cooperating with a fixed contact finger IOI. The

contact fingers I00 and IOI of each contact are secured respectively to terminal posts I02 and 103 mounted on an insulating terminal board I04 secured at its ends to the opposite sides of the casing 60. The lower end of each movable finger extends intoand cooperates with an open end slot I05 formed in an insulating block I06 secured to the vertical arm of an L-shaped bracket I01, the horizontal arm of which is secured to the underside of the armature 84. The parts are so proportioned that the movable contact fingers I00 will be moved out of engagement with the associated fixed contact fingers I0l by means of the bracket I01 and blocks I06 to open the contacts l00-IOI formed by these fingers, but that, when the armature is moved to its attracted position, the contact fingers I00 will then be moved into engagement with the fixed contact fingers IN to close the contacts I00-IOI. The contacts I00- IOI may be used to indicate the locked or unlocked position of the lock, or for any other desired purpose.

It should be noted that while as shown the contacts l00-IOI are so arranged that they will be open or closed according as the armature 84 is released or picked up, by reversing the positions of the contact fingers I00 and IOI these contacts can be made to be closed when the armature is released and opened when the armature is picked Pivotally supported between the armature 84 and the auxiliary lock rod 12 is a crank H0, the lower arm of which is provided at its free end with an inclined cam surface Il0a which oowhen the armature occupies its operates with an oppositely inclined cam surface 211 formed on a cam dog II2 secured to the upper side of the lock rod. The vertical arm of the crank H0 is provided with two adjusting screws H3, and the crank is constantly biased to the position in which the screws engage the rear side of the vertical arm of the bracket I01 by means of a compressed coil spring H4 interposed between the rear side of the vertical arm of the bracket and a fixed spring guide I I5. The adjusting screws are so adjusted that the spring H4 will act through the bracket IIO, screws H3 and bracket I01 to exert a force on the armature 84 to bias it to its released position in which the dog I5 enters the notch I3. With this adjustment oi the screws the spring H4 acts to keep the crank in the proper position to cooperate with dog H2, and also serves to prevent objectionable vibration of the parts.

Thecrank IIO also operates two contacts I20-- I2I, similar to the contacts I00-IOI through the medium of contact blocks I22 secured to the upper end of the vertical arm of the crank. The contact blocks I22 are similar to the blocks I06 and engage the lower ends of the movable fingers I20 in the same manner that the lower ends of the blocks I06 engage the fingers I00. The contact fingers I20 and I2I are secured to terminal posts I02 and I03, respectively, mounted in the central portion of the block I04. The contacts I20--I2I are employed to control the energization of the magnet M in a manner which will be made clear below.

The operation of the apparatus as a whole is as follows: When the switch A and the switch operating mechanism B occupy their normal positions as shown in Fig. 1, the parts of the electric lock occupy the positions in which they are shown in Fig. 5. That is to say, the padlock 61 is inserted in the eye 66b of the lever latch so that the lever latch and foot pedal 69 are held in their normal positions in opposition to the bias of the centering spring SI, the auxiliary lock rod I2 is held in its left-hand position in which the notch 13 is in alignment with the dog I5 and the notch I4 is out of alignment with the lock bar 5|, the electromagnet M is deenergized so that armature 88 is released and dog I5 is within the notch I3, dog H2 is out of engagement with the crank H0, and the contacts I00-IOI and I2Q-I2I are all open.

I shall now assume that it is desired to operate the switch to its reverse position. To do this, the padlock 01 is first removed from the eye. 6%. This permits the centering spring to move the lock rod T2 to its intermediate position, which movement, in turn, moves the foot pedal 59 in a counterclockwise direction and the lever latch 66 in a clockwise direction from the extreme positions shown in Fig. 5 to intermediate positions. This movement of the lever latch, however, is not sufiicient to permit the hand throw lever 30 to be withdrawn from the jaw 63. The movement of the auxiliary lock rod to its intermediate position also causes dog II2 to engage the end of crank I I0 and rotate this crank in opposition to the bias of the spring II4 to a position in which the contacts I20I2I become closed. The contacts I20- I2I are intended to be included in an energizing circuit for the magnet M, which circuit is not shown in the drawings, but which will be controlled by trafiic conditions in advance in such manner that if trafiic conditions in advance are safe for traiiic to proceed over the switch A when the contacts become closed, the magnet M will become energized automatically. One control circuit of this type is shown in Fig. 4 of Letters Patent of the United States No. 1,126,834, granted to W. P. Neubert et al. on February 2. 1915. Assuming that magnet M becomes energized when contacts I20-I2I become closed, armature 84 will move to its attracted position, and will thus withdraw the dog "I5 from the notch I3 to thereby unlock the auxiliary lock rod. The movement of the armature to its attracted position will also operate the contacts I00-IOI to provide a means for indicating at a remote point the fact that the auxiliary lock rod has become unlocked. As soon as the auxiliary lock rod becomes unlocked, the foot pedal 69 may be depressed to its lowermost position. The depression of this foot pedal moves auxiliary lock rod I2 to the right to the position in which the notch I4 aligns with the lock bar 5|, and also moves the lever latch 66 in a clockwise direction, as viewed in Fig. 5, to the position in which it is out of the path of movement of the lever 38 out of the jaw 63. Since the lever latch is now out of the path of movement of the lever 38 and the notch 14 is in alignment with the lock bar the hand throw lever l3 may be operated to reverse the switch points in the usual manner, as described hereinbefore. When this is done, the resultant movement of the lock bar 5! causes the notch 5m to move out of alignment with the auxiliary lock bar and causes the body of the lock bar to enter the notch '14. With the lock bar in the notch 14, the auxiliary lock rod is retained in its right-hand extreme position, and the parts of the lock will therefore be held in the positions they then occupy until the hand throw lever is returned to the position shown even though the foot pedal 69 is released. As a result, the foot pedal may be released as soon as the hand throw lever 38 has been raised a small amount from its normal position, and all contacts of the circuit controller will continue to remain closed until,

the lever 38 is returned to its normal position.

When it is desired to again restore the parts to the positions shown, the hand throw lever I3 is restored to its normal position. This automatically moves the lock bar 5| to its locking position in which the notch 5ia, aligns with the auxiliary lock rod, and hence releases the auxiliary lock rod. The spring 9| thereupon restores the auxiliary lock rod to its intermediate position, and hence moves the foot pedal 69 and lever latch 6! to their intermediate positions. In the intermediate position of the lever latch the eye 68b is not clear of the lips 64a and in order to reinsert the padlock 61 into the eye 661) it is necessary to restore the lever latch to its counterclockwise extreme position, in which it is shown in Fig. 5. This can be done by applying pressure to the treadle portion 650 of the latch, and when this is done, the resultant movement of the auxiliary lock bar will cause the cam dog I! 2 to move out of engagement with the cam surface I Illa on the crank I Ill. The parts are so proportioned that when the cam dog H2 is moved out of engagement with the cam arm I ID, the force exerted by the spring H4 will act through the arm N8, the screws H3, and bracket It! to force the armature to its lowermost position in opposition to the pull of the magnet, whereupon dog will reenter the notch 13 in the auxiliary lock rod. Furthermore, the movement of the armature to its lowermost position will open the contacts !lllllll while the accompanying movement of the arm I Hi will open the contacts l2il-l2l and hence will deenergize magnet M. When magnet M becomes deenergized, all parts will be restored to the positions shown.

Although I have herein shown and described only one form of electric lock embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. The combination with a switch operating mechanism including a hand throw lever movable between normal and reverse positions for moving the switch between its normal and reverse positions and a lock bar movable to a locking position in which it looks the switch in its normal position when said hand throw lever is moved to its normal position, of an electric lock comprising a casing secured to said switch operating mechanism and receiving one end of said lock bar, a lock rod slidably mounted in said casing for movement between two extreme positions and cooperating with said lock bar in such manner that said lock rod can only be moved between its two extreme positions when said lock bar occupies its locking position and that when said lock rod is moved to its one extreme position and said lock rod is subsequently moved away from its locking position said lock rod will be retained in said one extreme position until said lock rod is returned to its locking position, means biasing said lock rod to a position intermediate its two extreme positions, means connected with said lock rod for moving it in opposition to its bias from its intermediate to its one extreme position, a notch provided in said lock rod, a dog biased to a position inwhich it enters said notch and effective when in said notch to prevent movement of said lock rod toward its one extreme position past its intermediate position, electromagnetic means effective when energized to withdraw said dog from said notch, a contact for controlling the energization of said electromagnet, means operated by said lock rod for operating said contact when said lock rod is moved away from its other extreme position, a latch operatively connected with said lock rod and effective to prevent movement of said hand lever from its normal position except when said lock rod is moved to its one extreme position, and means for locking said latch in the position corresponding to said other extreme position of said lock rod.

2. The combination with a switch operating mechanism including a hand throw lever movable between normal and reverse positions for moving the switch between its normal and reverse positions and a lock bar movable to a locking position in which it looks the switch in its normal position when said hand throw lever is moved to its normal position, of an electriclock comprising a casing secured to said switch operating mechani'sm and receiving a part'of said lock bar, a lock rod slidably mounted in said casing for movement between two extreme .positions and cooperating with said lock bar in such manner that it can only be moved between its two extreme positions when said lock bar occupies its locking position and that when said lock rod is moved to its one extreme position and said lock bar is subsequently moved away from its locking position said lock rod will be retained by said lock bar in said one extreme position until said lock rod is returned to its locking position, means biasing said lock rod to a position intermediate its two extreme positions, means for moving said lock bar in opposition to its bias from its intermediate to its one extreme position, a notch provided in said lock rod, a dog biased to a position in-which it enters said notch and effective when in said notch to prevent movement of said lock rod toward its one extreme position past its intermediate position, electromagnetic means efiective when energized to withdraw said dog from said notch, a lever latch operatively connected with said lock rod and effective to prevent movement of said lever away from its normal extreme position except when said lock rod is moved to its one extreme position and for at times moving said lock rod to its other extreme position in opposition to its bias, means for locking said lever latch in the position corresponding to said other extreme position of said lock rod, a contact for controlling the energization of said magnet, a cam dog secured to said lock rod, and means operated by said cam dog for operating said contact when said lock rod is moved away from its other extreme position.

3. The combination with a switch operating mechanism including a hand throw lever movable between normal and reverse positions for moving the switch between its normal and reverse positions and a lock bar movable to a locking position in which it locks the switch in its normal position when said hand throw lever is moved to its normal position, of an electric lock comprising a casing secured to said switch operating mechanism and receiving a part of said lock bar, a lock rod slidably mounted in said casing for movement between two extreme positions and cooperating with said lock bar in such manner that it can only be moved between its two extreme positions when said lock bar occupies its locking position and that when said lock rod is moved to its one extreme position and said lock bar is subsequently moved away from its locking position said lock rod will be retained by said lock bar in said one extreme position until said lock rod is returned to its locking position, means biasing said lock rod to a position intermediate its two extreme positions, means for moving said lock bar in opposition to its bias from its intermediate to its one extreme position, a notch provided in said lock rod, a dog biased to a position in which it enters said notch and effective when in said notch to prevent movementof said lock rod toward its one extreme position past its intermc diate position, electromagnetic means efiective when energized to withdraw said dog from said notch, a lever latch opcratively connected with said lock rod and effective to prevent movement of said lever away from its normal extreme position except when said lock rod is moved to its one extreme position and for at times moving said lock rod to its other extreme position in opposition to its bias, means for locking said lever latch in the position corresponding to said other extreme position of said lock rod, a cam dog secured to said lock rod, a pivoted crank biased to one position and operable to another position by engagement with said cam dog in response to movement of said lock rod away from its other extreme position, and a contact for controlling said electromagnet controlled by said crank.

4. The combination with a switch operating mechanism including a hand throw lever movable between normal and reverse positions for moving the switch between its normal and reverse positions and a lock bar movable to a locking position in which it looks the switch in its normal position when said hand throw lever is moved to its normal position, of an electric lock comprising a casing secured to said switch operating mechanism and receiving a part of said lock bar, a lock rod slidably mounted in said casing for movement between two extreme positions and cooperating with said lock bar in such manner that it can only be moved between its two extreme positions when said lock bar occupies its locking position and that when said lock rod is moved to its one extreme position and said lock bar is subsequently moved away from its locking position said lock rod will be retained by said lock bar in said one extreme position until said lock rod is returned to its locking position, means biasing said lock rod to a position intermediate its two extreme positions, means for moving said lock bar in opposition to its bias from its intermediate to its one extreme position, a notch provided in said lock rod, a dog adapted to enter said notch and effective when in said notch to prevent movement of said lock rod toward its one extreme position past its intermediate position, an electromagnet disposed above said lock rod, an armature controlled by said electromagnet and operatively connected with said dog, said armature being biased by gravity to a released position in which said dog enters said notch and movable in response to cnergization of said electromagnet to another position in which said dog is withdrawn from said notch, a lever latch operatively connected with said lock rod and effective to prevent movement of said lever away from its normal extreme position except when said lock rod is moved to its one extreme position and for at times moving said lock rod to its other extreme position in opposition to its bias, means for locking said lever latch in the position corresponding to said other extreme position of said lock rod, a contact for controlling the energization of said magnet, a cam dog secured to said lock rod, and means operated by said cam dog for operating said contact when said lock rod is moved away from its other extreme position.

5. The combination with a switch operating mechanism including a hand throw lever movable between normal and reverse positions for moving the switch between its normal and reverse positions in which it locks the switch in its normal position when said hand throw lever is moved to its normal position, of an electric lock comprising a casing secured to said switch operating mechanism and receiving a part of said lock bar, a lock rod slidably mounted in said casing for movement between two extreme positions and cooperating with said lock bar in such manner that it can only be moved between its two extreme positions when said lock bar occupies its locking position and that when said lock rod is moved to its one extreme position and said lock bar is subsequently moved away from its locking position said lock rod will be retained by said lock bar in said one extreme position until said lock rod is returned to its locking position, means biasing said lock rod to a position intermediate its two extreme positions, means for moving said lock bar in opposition to its bias from its intermediate to its one extreme position, a notch provided in said lock rod, a dog adapted to enter said notch and effective when in said notch to prevent movement of said lock rod toward its one extreme position past its intermediate position, an electromagnet disposed above said lock rod, an armature controlled by said electromagnet and opcratively connected with said dog, said armature being biased by gravity to a released position in which said dog enters said notch and movable in response to energization of said electromagnet to another position in which said dog is withdrawn from said notch, a lever latch operatively connected with said lock rod and eliective to prevent movement of said lever away from its normal extreme position except when said lock rod is moved to its one extreme position and for at times moving said lock rod to its other extreme position in opposition to its bias, means for locking said lever latch in the position corresponding to said other extreme position of said lock rod, a cam dog secured to said lock rod, a pivoted crank biased to one position and operable to another position by engagement with said cam dog in response to movement of said lock rod away from its other extreme position, and a contact for controlling said eleotromagnet controlled by said cam dog.

6. The combination with a switch operating mechanism including a hand throw lever movable between normal and reverse positions for moving the switch between its normal and reverse positions and a lock bar movable to a locking position in which it looks the switch in its normal position when said hand throw lever is moved to its normal position, of an electric lock comprising a casing secured to said switch operating mechanism and receiving a part of said lock bar, a lock rod slidably mounted in said casing for movement between two extreme positions and cooperating with said lock bar in such manner that it can only be moved between its two extreme positions when said lock bar occupies its locking position and that when said lock rod is moved to its one extreme position and said lock bar is subsequently moved away from its locking position said lock-rod will be retained by said lock bar in said one extreme position until said lock rod is returned to its locking position, means biasing said lock rod to a position intermediate its two extreme positions, means for moving said lock bar in opposition to its bias from its intermediate to its one extreme position, a notch provided in said lock rod, a dog adapted to enter said notch and elfective when in said notch to prevent movement of said lock rod toward its one extreme position past its intermediate position, an electromagnet disposed above said lock rod, an armature controlled by said electromagnet and operatively connected with said dog, said armature being biased by gravity to a released position in which said dog enters said notch and movable in response to energization of said electromagnet to another position in which said dog is withdrawn from said notch, a bracket secured to said armature, contacts operatively connected with said bracket, a cam dog secured to said lock rod, a pivoted crank biased to one position and operable to another position by engagement with said cam dog in response to movement of said lock rod away from its other extreme position, means connecting said pivoted crank with said armature through the medium of said bracket in such manner that the biasing means for said crank assists in biasing said armature to its released position, the parts being so proportioned that the combined biasing force of gravity and said spring on said armature is sufiicient to overcome the pull of said electromagnet when said cam dog is out of engagement with said crank, and a contact for controlling said electromagnet controlled by said crank.

KENNETH J. J. MCGOWAN. 

